Proportional dividers.



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PATENTED=JUN-152,l 1903. y

i UNTTEDn STATES Patenteaoune a, i903.

PATENT OFFICE.

FFOPORTION'AL` DIVIDERS.

SPECIFICATION forming part of Letters Patent No. 730,105,1dated'3' une 2, 1903. Application iilecl September 5,1902p Serial No. 122,203. (No model.)

To all whom, it may concern:

Be it known that I, CHARLEskFesBY, a citizen of the United States, residing in Rutherford, in the county of Bergen and State of New Jersey, have invented a certain new and useful Improvement in Proportional Dividers, of which the following is a specification.

The invention relates to instruments for proportionally increasing or decreasing measurements in making enlarged or reduced copies, and is designed more especially for service in laying out the required pattern of cutter or knife to produce a molding of desired pattern.

The cutters of a molding-machine are secured to the plane faces of the cutter-head at points removed from the center of'rotation, and as they are not radial to the latter the contour of the cutting edge of each knife requires to be somewhat different from the proleof the finished molding.v

The object of my invention is to provide an easily-operated instrument by which the cutters to produce any desired pattern may be quickly and accurately laid out and by which the cutters may be properly adjusted on the cutter-head. A

The invention consists in certain combinations and arrangements of parts by which the above objects are attained, to be hereinafter fully described.

The accompanying drawings form a part of this specification and show the invention as I have carried it out. p

Figure l is a diagram showing the cutterhead of a molding-machine and illustrating the difference in contour of the knife and molding.v Fig. 2 is a face or front View of the instrument. Fig. 3 is a corresponding View of the opposite face. Fig. 4. is a corresponding edge view, and Fig. 5 is a transverse section taken on the line 5 5 in Fig. 3.

Similar letters ofreference indicate the.

the direction to act upon the-face of the wood strip, as will be understood. A4 is a dotted 'line drawn through the axis of the cutter-head and intersecting the base-line A3 at a right angle, and A2 is aline in the plane of the cutting edge of the knife parallel with the line A4. At B is shown inA full lines a pattern of a molding to be produced, erected on the base-line A3. A series of lines A5, drawn parallel with the base-line,pass through the several angles of the pattern and are extended tothe axial line A4, whence they are projected in segments of circles from the axis of the cutter-head to the line A2 and thence are again projectedin straight lines A6 parallel with the base-line. The contour of the cutting edge of the knife may be laid out on these lines, as shown by the heavy dotted lines at A7. It will be observed by comparing this contour with the pattern B (again shown for convenience in comparison by the lighter dotted lines at B within the lines A7)-that the lines indicating width of the several .members comprising the molding are unchanged, but that the lines indicating depth are considerably increased in length, and, further, that the difference is more marked or proportionately greater near the cutter-head because of the greater angle produced by the shorter radius.

My improved instrument is designed to correspondingly increase the vertical measurements of thepattern in laying out the knife and also to provide for the slight change in proportion due to the difference in radial distance, as pointed out above.

Referring to Figs. 2, 3, 4., and 5, in which the instrument is shown,C is the main member, preferably of thin metal,having twofoppositely-extending fixed legs C C2, terminating in points C301. D is a member of similar material pivoted Ato the member C at d near the rootoof the leg C and having the leg D extending approximately parallel with the leg C2 and terminating in the point D3 adjacent to the point C4. A short oppositelyextending arm'D2 terminates in a boss or abutmentD against which im pinges-the end of a screw M, passing through a. threaded lug C5 on the leg C and having a milled head M, by whichiit may be advanced or withdrawn. A third member E, pivotally connected to the member C at e near the root of stant.

the leg C2, has a leg E and point E2 extending in the same direction as the leg C and has also an arm E3 extending across the leg D and carrying a pin E, having a lipped head E5, by which the leg D' is engaged. On the opposite face of the member C is a cap or hollow casing F, containing a coiled spring F', having an arm F2 extending outwardly and engaging a pin E6 on the leg E and exerting its force in the direction to close the instru ment by drawing the leg E' toward its mate C' at one end and, through the engagement of the arm E2 with the leg D'` also drawing the latter toward its mate C2 at the opposite end of the instrument. The instrument is opened and set by turning the screw M in the direction to force the abutment D4 away from the lng C5, thus separating both pairs of legs. Any measurement taken by the points C4 D3 will be proportionately increased at the points C3 E2`by reason of the greater movement of the leg E', due to the difference in length of such leg and its arm E3, and also to the point of engagement of the latter with the leg D', as will be understood, and, so far as yet described, the ratio will be nearly con- Iu order to induce the required lessening of the ratio as the measurements increase in depth in laying out the knife, the slightly-curved incline D5 is provided to re ceive the pin E4 and cause the latter in its sliding engagement with the leg D to descend the incline as the space between the legs C2 and D' widens and to ascend the incline as such space becomes less. By properly shaping the incline relatively to the position of the pivots d and e and other elements determining the proportions the instrument will compensate very exactly for the increasing fiatness of the curves described by those portions of the knife having increased radial length.

In using the instrument for the purpose described the pattern of the desired molding is first laid out upon a predetermined baseline representing the bed of the molding-machine, with as many vertical ordinates and corresponding cross-lines as may be necessary or desired, and the Width measurements transferred without change to similar ordinates and lines on the knife pattern. The several depth measurements are then taken by the points C4 D3 and applied to the knife pattern by reversing the instrument and pricking off the distances indicated by the points C3 E2. By joining the several points thus obtained the knife pattern is completed. `The instrument also serves a use ful function in exactly indicating the projection the blades should have relatively to the cutter-head and to the base-line of the molding pattern in setting the knives.

Although I have described the invention as designed for use in connection with moldingmachines, it will be understood that it lnay serve for other purposes and may be modified in the forms and proportions of its parts to conform to the requirements of such service.

l. In proportional dividers, two pairs of oppositely-extending legs pivotally connected and means for simultaneously adjusting both pairs of legs, the distance between the terminals of one pair being greater than that between the terminals ot' the other pair, in combination with means for automatically varying the ratio between the said distances as the latter are increased or diminished.

2. A member C having two oppositely-extending fixed legs C C2, a member D pivotally mounted thereon having a leg D' extending approximately parallel with the leg C2 to form a pair therewith, a member E pivotally mounted on said member C and having a leg E' extending approximatelyparallel with the leg C' to form an opposite pair, and an arm E3 engaging said leg D', in combination with means for separating the legs of said pairs simultaneously and for drawing them together.

A member C having two oppositely-extending fixed legs C' C2, a member D pivotally mounted thereon having a leg D extending approximately parallel with the leg C2 to form a pair therewith, a member E pivotally mounted on said member C and having aleg E extending approximately parallel With said leg C' to form an opposite pair, an inclineD5 on said leg D', an arm E3 on said member E having a pin E4 engaging said incline, and means for separating the legs of said pairs simultaneously and for drawing them together, all combined and arranged to serve substantially as herein specified.

4. The member C having the legs C C2, the member D pivotally mounted thereon and having the leg D' and abutment D4, the member E pivotally mounted on said member C and having the leg E' and an arm E2 engaging said legD',a lug C5on said leg C', ascrew in said lug impinging against said abutment and serving to separate said legs, and a spring serving to draw said legs together, all combined substantially as herein specified.

5. A member C having two oppositely-extending fixed legs C C2, a memberD pivotally mounted thereon havinga leg D' extend ing approximately parallel with the leg C2 to form a pair therewith, a member E pivotally mounted on said member C and havingaleg E' extending approximately parallel with said leg C' to form an opposite pair, an incline D5 on said leg D', an arm E3 on said member E having a pin E4 engaging said incline, an abutment D"v on said member D, a screw M carried on said xed leg C' and impinging against said abutment, a spring F and cap F therefor carried on said member C and engaged with said leg E',said screw and spring serving as means for separating the legs of said pairs simultaneously and for drawing them together, all combined and arranged to IOO IIO

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serve substantially'as and for the purposes set forth.

6. In proportional dividers, two pairs of op- A positely-extending legs, means for xedly,

pvotally connecting the same and means for simultaneously adjusting rboth pairs of legs, the. distance between the terminals of one pair being greater thanthat between the terminals of the other pair, combined with means for automatically varying the ratio between the said distances as the latter are increased or diminished. r

7. In proportional dividers, a member having opp'ositely-extending fixed legs, oppo sitely-extending legs pivotally mounted there.

on on fixed pivots, means on said member for simultaneously adjusting both of said pivoted legs, said legs being of different lengths, and meansfor automatically varying the ratio zo between the distances between the adjacent ence of two witnesses.

terminals of the legs as said distances are increased or. diminished.

8. In proportional-dividers a member having oppositely-extending legs, a member pivotally mounted thereon and having a leg c0 operating with one of the legs ofthe first-mentioned member, a member pivotally mounted on the firstmentioned member and having a leg coperating' with the other leg thereof, combined with means for automatically varying the proportions of the spaces between the terminals of each pair of` legs, substantially as described. n

In testimony that Il claim the'inventionl above setforth I aftix my signature in pres- CHARLES FOSBY.

Witnesses:

CHARLES R. SEARLE, RoB'r. CONNOR. 

